Improving the Stochastic Resonance in a Bistable System with the Bounded Noise Excitation

The stochastic resonance (SR) phenomenon is investigated in a typical bistable system that excited by the bounded noise and the weak low-frequency signal simultaneously. Based on numerical simulations, the main results are obtained. The SR performance mainly depends on the mean frequency and is influenced by the randomness level of the bounded noise. It occurs when the mean frequency is much larger than or approximates the signal frequency. However, the SR almost disappears when the mean frequency is much smaller than the signal frequency. By introducing an auxiliary high-frequency signal in the excitations, another phenomenon called as vibrational resonance (VR) appears. With the cooperation of VR, the SR performance is greatly improved. The results in this paper give a reference to deal with the weak signal submerged in the bounded noise.